【摘要】 为对比研究超临界态CO₂、液态CO₂和气态N₂注入采空区的防灭火性能,自主研制了模拟采空区残煤自燃过程实验系统,开展了超临界态CO₂、液态CO₂和气态N₂注入采空区防灭火实验。实验结果表明:12 MPa、39℃超临界态CO₂对采空区自燃残煤的降氧降温能力优于6 MPa、30℃液态CO₂优于6 MPa、39℃气态N₂;12 MPa、39℃超临界态CO₂对残煤的降温能力是6 MPa、30℃液态CO₂的1.7倍,是6 MPa、39℃气态N₂的10倍,对采空区的降温能力是液态CO₂的2倍,为气态N₂的8倍;12 MPa、39℃超临界CO₂对采空区的降氧速率比6 MPa、30℃液态CO₂和6 MPa、39℃气态N₂高12.5%;12 MPa、39℃超临界CO₂的降温能力是8 MPa、39℃超临界CO₂的1.7倍,因此适当提高超临界态CO₂的注入压力,防灭火性能更佳。更多还原

【Abstract】 For comparative study the fire-fighting performance of supercritical CO₂ and liquid CO₂ and gaseous N₂ injected into goaf, we have developed an experimental system simulating the spontaneous combustion process of residual coal of goaf independently. The fire-preventing and fire-extinguishing experiments were carried out with supercritical CO₂ and liquid CO₂ and gaseous N₂ injected into goaf. The experimental results show that the oxygen-lowering and cooling performance of supercritical CO₂ under 12 MPa, 39 ℃ is superior to liquid CO₂ under 6 MPa, 30 ℃, and liquid CO₂ is superior to gaseous N₂ under 6 MPa, 39 ℃ on the residual coal of spontaneous combustion in goaf. The cooling capacity of supercritical CO₂ under 12 MPa, 39 ℃ on residual coal is twice that of liquid CO₂ under 6 MPa, 30 ℃, 10 times that of gaseous N₂ under 6 MPa, 39 ℃ and the cooling capacity of supercritical CO₂ on air is twice that of liquid CO₂ and 8 times that of gaseous N₂. The oxygen-lowering rate of supercritical CO₂ under 12 MPa, 39 ℃ on goaf is 12.5% higher than that of liquid CO₂ under 6 MPa, 30 ℃ and gaseous N₂ under 6 MPa, 39 ℃. The cooling capacity of supercritical CO₂ under 12 MPa, 39 ℃ is 1.7 times that of supercritical CO₂ under 8 MPa, 39 ℃. Therefore, it is better to increase the injection pressure of supercritical CO₂ appropriately for the fire-fighting performance.更多还原